Liquid dispenser with sealing module

ABSTRACT

A sliding stem seal assembly for a fluid dispenser. In one embodiment, an insertable module retains a stem seal and a housing seal even when disengaged from the housing of the dispenser. The module isolates the stem seal from the housing such that it contacts the stem and a low friction surface of the module, and the module also isolates the housing seal from movement of the stem, for reduced wear from the housing and the moving stem.

RELATED APPLICATION

This application is related to U.S. patent application Ser. No. ______(Attorney Docket No. 3356-179) filed on Nov. 18, 2004, entitled LiquidDispenser with Stem Sealing System, the entire disclosure of which ishereby incorporated herein by reference.

TECHNICAL FIELD

This invention relates generally to liquid dispensing devices, and moreparticularly to seal assemblies for liquid dispensing devices.

BACKGROUND OF THE INVENTION

Fluid dispensers include a variety of components for selectivelycontrolling the flow of and dispensing a fluid. Fuel dispensing systemscan include, for example, a stem for assisting in actuating a poppetvalve between opened and closed positions to control fluid flow betweenan inlet and outlet port. For instance, a fluid dispensing system isdescribed in U.S. Pat. No. 3,811,486 (the '486 Patent) to Wood, theentire disclosure of which is hereby incorporated herein by reference.

Fluid dispensing assemblies or nozzles can comprise a main body with aninlet port adapted to communicate with a source of pressurized fluid,and an outlet port adapted to dispense fluid from the main body. In suchdevices, a stem, for actuating a valve, slides relative to a seal or toa packing (typically loose material stuffed around the stem in achamber). As described in further detail in the referenced '486 patent,the stem, together with a lever, can assist in actuating the valve, suchas a poppet valve, to control fluid dispensing.

Typically, the packing, an O-ring or a related flanged lip seal has beenprovided to prevent leakage of fluid along the stem, and moreparticularly between the stem and portions of the main body. In somedevices, a flanged lip seal with an internal O-ring energizer has beenutilized.

However, such seals and sealing systems have exhibited problems withrespect to sealing performance and/or durability. For example, suchseals may exhibit rapid deterioration and wear from movement within thedispenser. Accordingly, the seal can become quickly compromised,resulting in leakage of the fluid. In addition, such seals typicallyhave an inner surface which seals against the moving stem, or othercomponent, and an outer surface which seals against the stationarydispenser body. Friction from movement of the seal caused by movement ofthe stem can compromise the sealing surface against the stem as well asthe sealing surface against the stationary body.

In addition, inserting a seal into a dispensing device can be timeconsuming and tedious. The seal is typically small and required to befitted within a narrow chamber. Often, specialized tools are required tocompress the seal and place it into the housing of the dispenser againstthe components being sealed.

SUMMARY OF THE INVENTION

Accordingly, it is desired to obviate problems and shortcomings ofconventional seal assemblies. More particularly, in some embodiments, itis desired to provide improvements in durability and/or performance ofseals in fluid dispensing apparatus. Moreover, in some embodiments, itis desired to reduce the difficulty and minimize the time needed forassembling a fluid dispensing apparatus.

According to one aspect, a fluid dispenser is provided comprising afluid dispenser housing having an inner chamber defined by a chambersurface, and a cylindrical stem that includes an outer surface. The stemis configured to control the flow of fluid through said housing. Thedispenser also includes an insertable module which is selectivelyengaged with said inner chamber and includes an opening slidinglyreceiving said stem. A stem seal member is retained by said module andis in sealing contact with the outer surface of the cylindrical stemwhen the module is engaged with the inner chamber to provide a firstseal. The stem seal member is separated from the housing by a portion ofthe module and the said stem seal member contacts the stem and asubstantially non-porous portion of said module. The assembly alsoincludes a housing seal member retained by the module and in sealingcontact with the chamber surface of the housing when the module isengaged with the inner chamber to provide a second seal. The housingseal member is separated from the stem by a portion of the modulewhereby the second seal provides a static seal against the chambersurface. The module is configured to retain the stem seal member and thehousing seal member when the module is disengaged from the chamber.

According to another aspect, a fluid dispensing assembly is providedcomprising a main body including an inlet port adapted to communicatewith a source of pressurized fluid and an outlet port adapted todispense fluid from said main body, the main body including an innerchamber defined by a chamber surface. The assembly also includes a stemhaving an outer surface, wherein the stem is adapted to assist inregulating fluid between said inlet port and said outlet port of saidmain body. In addition, the assembly includes a stem seal having anopening slidably receiving the stem and comprising an inner sealingsurface, wherein the inner sealing surface sealingly contacts the outersurface of the stem to provide a first seal. In addition, the assemblyincludes a body seal sealingly contacting the chamber surface of thebody to provide a second seal, and a module configured to selectivelyengage the inner chamber and including an opening for receiving thestem. The module is adapted to retain the stem seal and the body sealwhen the module is disengaged from the chamber. The stem seal providesthe first seal against the stem when the module engages the innerchamber and the body seal provides the second seal against the chambersurface when the module engages the inner chamber. The assembly furtherincludes a manual actuator adapted to control movement of the stem andcontrol the flow of fluid through the main body.

According to an additional aspect, a fluid dispenser is providedcomprising a main body including an inlet port adapted to communicatewith a source of pressurized fuel and an outlet port adapted to dispensefuel from said main body, wherein said main body includes an innerchamber defined by a chamber surface. The dispenser also includes a sealhaving a sealing surface, wherein the sealing surface sealingly contactsa component of the fuel dispensing assembly to provide a first seal. Thedispenser also comprises an insertable retainer configured toselectively engage the inner chamber, wherein the retainer is adapted toretain the seal when the retainer is disengaged from said chamber, andwherein the seal provides the first seal against the assembly componentwhen the retainer engages the inner chamber. The dispenser also includesa manual actuator adapted to control the flow of fuel through the mainbody, and a shut-off actuator configured to automatically shut off flowof fuel through the main body in response to a fill condition.

According to another aspect, a method for assembling a fuel dispensingapparatus is provided, the method comprising placing a seal on a modulesuch that the seal is held on said module, and providing components forassembling a fuel dispensing apparatus. The method also comprisesengaging the module with a housing for a fuel dispensing apparatus, suchthat the seal contacts at least one of the housing and the componentsand provides a fluid-tight seal therewith. The method further comprisesassembling the components and the housing as a fuel dispensingapparatus.

In accordance with another aspect, a fluid dispenser is providedcomprising a fluid dispenser housing having an inner chamber defined bya chamber surface, and a poppet stem assembly residing within the innerchamber. The poppet stem assembly comprises a cylindrical stem includingan outer surface, the stem being configured to control the flow of fluidthrough the housing. The assembly also includes a stem seal member insealing contact with the outer surface of said cylindrical stem toprovide a first seal, wherein the stem seal member does not contact saidhousing. In addition, the assembly includes a housing seal member insealing contact with the chamber surface of the housing to provide asecond seal, wherein the housing seal member does not contact the stem.

Still other aspects of the present invention will become apparent tothose skilled in the art from the following description wherein thereare shown and described alternative illustrative embodiments includinginventive aspect. These embodiments and descriptions are provided onlyas illustrative examples, and in no way are intended, nor should they beinterpreted, as limiting. As will be realized, the invention is capableof other different embodiments, all without departing from the scope ofthe invention. These other possible embodiments will be understood bythose skilled in the art based upon the description and teachingsherein. Accordingly, the drawings and descriptions should be regarded asillustrative and exemplary in nature only, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the inventive aspects, it is believed the samewill be better understood from the following description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a partial sectional view of an illustrative embodiment of afluid dispensing assembly, made and operating in accordance withprinciples of the present invention;

FIG. 2 a is a cross sectional view of an illustrative embodiment of apoppet stem seal module, made and operating according to principles ofthe present invention;

FIG. 2 b is a perspective view of the module of FIG. 2 a;

FIG. 3 a is a cross sectional view of an illustrative embodiment of aseal that can be used in the stem seal module of FIGS. 1 and 2, inaccordance with principles of the present invention;

FIG. 3 b is a top view of the seal of FIG. 3 a;

FIG. 4 a is a perspective view of an illustrative embodiment of thecantilever spring of the seal of FIGS. 3 a and 3 b;

FIG. 4 b is a perspective view of the seal of FIGS. 3 a and 3 b;

FIG. 5 is a partial sectional view of another illustrative embodiment ofa fluid dispensing assembly, made and operating in accordance withprinciples of the present invention;

FIG. 6 is a cross sectional view of an illustrative embodiment of afueling nozzle which includes the insertable poppet stem seal module ofFIG. 2, and which is made and operating according to principles of thepresent invention; and

FIG. 7 is a cross sectional view of an illustrative embodiment of afueling nozzle which includes the insertable poppet stem seal module ofFIG. 5, and which is made and operating according to principles of thepresent invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 depicts a fluid dispensing assembly 10, made and operating inaccordance with principles of the present invention. The fluiddispensing assembly 10 includes a main body 12 with an inlet port 14adapted to communicate with a source of pressurized fluid. For instance,in fuel dispensing applications, a high pressure fuel hose can beremovably connected to the inlet port 14 to allow a fuel pump (notshown) such as in a gasoline station to act as a source of pressurizedfuel for the fuel nozzle 10. The fluid dispensing assembly 10 furtherincludes an outlet port 16 adapted to dispense fluid from the main body12. In fuel dispensing applications, the outlet port 16 can take theform of a familiar spout or other device adapted to communicate with theinlet opening of a vehicle fuel tank.

As further illustrated in FIG. 1, the fluid dispensing assembly 10 mayinclude a sliding stem seal assembly 18, wherein a stem 20 may axiallyreciprocate relative to a stem seal member 50 as discussed more fullybelow. The stem 20 is adapted to assist in regulating fluid between theinlet port 14 and the outlet port 16. For example, as illustrated inFIG. 1, the stem 20 can assist in actuating a valve, such as a poppetvalve 26. In order to dispense fluid, an operator will move theactuator, such as lever 13, and the stem 20 therewith, upwardly relativeto the main body 12 to open the valve 26. When the stem 20 moves backdownwardly, such as under a bias force, the valve 26 closes. To reducewear and friction between the stem 20 and the lever 13, the stem 20 maybe provided with an optional wear resistant tip 24 made from a materialwith a relatively low coefficient of friction.

In this embodiment, the seal 50 is retained by an insertable andremovable module 28, according to principles of the present invention.The module 28 can be selectively engaged with the main body 12, such asvia threads or other suitable engagement methods. The module 28 caninclude multiple components for retaining and holding the seal 50, whichprovides a seal against the stem 20. The module 28 holds the seal 50even when the module is disengaged from the main body 12. In thisembodiment, module 28 also retains a seal 48 which provides a sealagainst the main body 12. As will be discussed in more detail below, themodule 28 of this embodiment can provide improved sealing performanceand durability, as well as increase the ease of assembling thecomponents of the stem seal assembly 18.

The removable seal module 28 of this embodiment is shown in more detailin FIG. 2 (comprising FIGS. 2 a and 2 b). As shown, this embodiment ofthe module 28 includes a stainless steel sleeve 30 having an internalpassage 32 for slidingly receiving the stem 20. The passage 32 includesa wide passage portion 31 at the upper end of the sleeve 30, whichtransitions to a narrow passage portion 33. The module 28 also includesa bushing 34 which is engaged within the wide passage portion 31 of thesleeve 30. The bushing 34 can be made from a plastic or other suitablelow friction material, such as a DELRIN material for example. Thebushing 34 can therefore be used, if desired, to reduce friction againstthe stem 20 as it moves axially within the module 28.

The module 28 retains one or more seals for use in the poppet valve stemseal assembly. In particular, in this embodiment, the sleeve 30 includesrecesses or voids for placement of two seals which resists leakage offuel as it flows through the dispenser. In this example, a first recesscomprises a groove 36 formed in the exterior of the sleeve 30. Withinthe groove 36 is held a housing seal member 48 to thereby retain theseal 48 within the module 28 when it is disengaged from the mainbody/housing 12 (FIG. 1). However, when the module 28 is inserted intothe housing 12, the seal 48 abuts the housing 12 to provide a fluidtight seal therewith to resist the leakage of fluid along the interfacebetween the module 28 and the housing 12. The seal 48 can comprise aring-like or other appropriate seal member, such as an O-ring made froma nitrile (e.g., Buna) material for instance.

In addition, the module 28 retains (e.g., houses) a second seal 50 forproviding a seal against the stem 20. Accordingly, this seal 50 islikewise retained by the module 28 prior to the module being engagedwith the housing 12. In particular, in this embodiment, the sleeve 30includes a recess 37 at one end, formed by a narrow wall portion 39 andan interior seat 38. Accordingly, the ring-like seal 50 resides withinthe recess 37 and against the seat 38, with the narrow wall 39surrounding the seal.

The module 28 can further include a guide or cap 42, for additionalsupport in retaining the seal 50. In particular, in this embodiment, thediameter of the end portion 43 of the guide 42 is approximately the sameas the inner diameter of the recess 37 between walls 39. Accordingly, aninterference fit or engagement is provided between the end portion 43 ofthe guide 42 and the recess 37 of the sleeve. Guide 42 can likewise bemade of a friction reducing material, such as DELRIN for example. Anextension 41 from the guide 42 can be provided as stop to abut the wall39 when the guide 42 is engaged with the sleeve 30.

Accordingly, with reference to FIGS. 1-2, seal 50 is held within twonested components (42 and 30) of the module 28, in this embodiment. Bytightly containing the seal 50 within the module 28 according toprinciples of the present invention, less movement of the seal 50results when the stem 20 axially slides against the seal 50 during use.Accordingly, better performance and durability can result. In addition,in this embodiment, a separate seal 48 is provided to seal against thehousing 12 of the dispenser. Seal 48 does not also seal against the stem20, decreasing its potential for any appreciable movement caused by thestem. Likewise, seal 50 does not seal against the porous housing,decreasing the potential for seal 50 to fail. In particular, it has beenfound that placement of a poppet stem seal 50 against a housing 12 cangradually wear the finish of the housing, as the seal moves slightly inresponse to movement of the stem 20, exposing the porous material of thehousing. The friction between the porous housing material and the seal50 can then quickly deteriorate the seal. In this embodiment, however,the seal 50 is isolated from and does not contact the housing 12, butrather contacts walls 39 of the sleeve 30, which, according toadditional aspects, can be made from a low friction, smooth, and/ornon-porous material, such as stainless steel for example. Because thesliding stem seal 50 contacts this material rather than the housing, ithas been found to exhibit improved durability, even though the seal maymove slightly within the module 28 as the stem 20 slides against theseal. In addition, because seal 48 is isolated from movement of the stem20 and does not contact the stem, it does not experience appreciablemovement and therefore does not experience frictional wear against theporous housing 12.

To assemble the module 28, seal 48 can be slided over the exteriorsurface of the sleeve 30 until it rests in groove 36. The bushing 34 isplaced into the chamber until it reaches the narrow passage 33 such thatit abuts and mates with the sleeve 30. Seal 50 can be placed into recess37, and guide 42 can be pressed into the recess 37 until extension 41reaches and is stopped by the bottom wall 39. Accordingly, the module 28is ready to receive the stem 20 and to be engaged with the housing 12.Thus, the seals 48 and 50 are assembled with and retained by the modulewhen it is disengaged from the fluid dispenser housing 12, and can belater placed into the fluid dispenser without the need for special toolsand without requiring difficult placements of small parts. Rather, theentire module 28 can be placed into the housing 12 as a complete unit,such as by engaging threaded portion 35 with a corresponding threadedportion 15 within the housing 12 (See FIG. 1). The stem 20 can be placedthrough the center of the sleeve 30, and its interior bushing 34 andseal 50, as well as through the center of the guide 42 engaged with thesleeve 30. All of these components in this embodiment therefore have apassage through their center having a diameter, at least at someportion, that is approximately the same as or slightly larger than thediameter 21 of the stem 20. Accordingly, stem 20 slides axially throughthe center of the module 28. The seal 50 in this example also includes aflared end such that its opening near that end is slightly smaller indiameter than the diameter 21 of the stem 20. Accordingly, after thestem 20 is inserted through the module 28, the flared end of the seal 50compresses somewhat between circular wall 39 and the exterior surface ofthe stem 20, providing a fluid resistant seal at the point ofcompression.

More specifically, as best seen in FIGS. 2-4, the seal 50 can include abase 56 and a flared end 51 with an inner flange 52 and an outer flange54. Inner flange 52 flares radially toward the stem 20 (i.e., in agenerally inward direction) while the outer flange 54 flares radiallyaway from the stem 20 (i.e., in a generally outward direction). In oneembodiment, the seal 50 is arranged such that the inner flange 52contacts the outer surface 22 of the stem 20 to create a seal therewithalong a circumferential contact surface, edge or lip 64. Because thestem 20 is round in this embodiment, the inner flange 52 provides afirst or inner ring-like seal at the contact surface, edge or lip 64. Inuse, the inner flange 52 is deflected slightly inward such that arelatively small portion of the inner flange 52 is in at least partiallycompressed contact with the outer stem surface 22. Providing a smallerarea of contact lowers the friction force between the stem and seal inuse, thereby improving the functionality (e.g., ease of actuation andsliding, with superior sealing) of the fluid dispensing assembly whilepreventing undue wear of either the seal 50 or the stem 20.

The seal 50 can also be arranged such that the outer flange 54 contactsan inner surface of the module sleeve 30 to similarly create a sealtherewith. The outer flange 54 thus provides a second or outer ring-likeseal adjacent the inner surface of the sleeve. In certain embodiments ofthe present invention, and as illustrated in FIG. 3 b, the firstring-like seal can be at least substantially concentric with the secondring-like seal, via surfaces 64 and 66.

The ring-like contact can be a knife-like contact (e.g., near surface,edge or lip 64, 66) or a limited vertical contact surface. The seal 50is thus provided in the shape of a torus or general donut shape havingan opening in the center (i.e., either in the center or off-centerdepending upon the application) to receive and sealingly engage the stem20 in use.

With reference to FIGS. 1-4, and according to at least some embodiments,the entire seal 50, or at least the outer surface of the flared end 51may be made of, or coated with, a material that reduces the coefficientof friction, improves durability when contacting fuel, and/or improvesabrasion resistance of the seal. For instance, the seal 50 may consistof entirely or essentially, or partially comprise, a friction reducingmaterial, such as a fluorocarbon polymer for example. In particular,polytetrafluoroethylene, fluorinated ethylene-propylene, ethylenetetrafluoroethylene, or perfluoroalkoxy may be utilized, such as thosetypes of materials marketed under the trademark TEFLON® (as availablefrom E.I. DuPont de Nemours). As an alternative, high performancefriction reducing elastomers, such as POLYMOD® (as available fromPolymod Technologies, Inc.), could be utilized, as could other frictionreducing material compatible with the seal 50 and the applicationrequirements. For example, elastomers which are polymer modified to havevery low coefficients of friction and optimized wear life could also beutilized.

It has been found that particularly advantageous performance anddurability (with respect to friction characteristics, and durability andsize stability when in contact with fuel) can be attained byconstructing substantially the entire seal 50 using a TEFLON material.In addition, the inner surface 74 of the sleeve 30 and/or the outersurface 22 of the stem 20 may be made of low friction materials and/orappropriately finished or coated/treated to further prevent unduefriction and wear, and to optimize the service life of the assembly. Inone example of a fuel dispenser nozzle stem, the outer surface 22 of thestem 20 may be optionally finished with a finish of at least 12 for usewith a seal 50 having a TEFLON coating, or comprising or consisting ofTEFLON. The material used to construct the seal 50, partially orcompletely, preferably results in a dynamic and/or static coefficient offriction relative to the stem of less than about 0.1, such as less thanabout 0.05 for example, which can result in improved performance of thefueling nozzle. In particular, according to one embodiment of theinvention, using a seal made from TEFLON and a stem made from stainlesssteel can provide a coefficient of friction of the seal relative to thestem of about 0.04.

As shown in FIGS. 1-4, the seal 50 of at least some embodimentsembodiment can also be energized such that the flared end 51 willinclude an appropriate positive or active outward radial bias to providesufficient pressure, and therefore provide a sufficient fluid seal tominimize any potential for leakage along the stem 20 and between thestem and the sleeve 30, when the nozzle is in either a low-pressure modeor a zero-pressure mode. As used herein, the term “energized” refers toany material, structure, or combination of material and structures whichtends to bias the inner and outer flanges outwardly from the seal bodyso that, in use, sealing contact can be positively or activelymaintained even where there are no fluid pressure forces compressing theseal. In one example the flared end 51 of the seal 50 includes a recess62 between the inner and outer flanges (as best shown in FIG. 4 b).Optionally providing the flared end 51 with a recess 62 permits theflared end to expand under the influence of fluid pressure to allow theouter surfaces of the flanges to also more efficiently seal as fluidpressure increases.

In another example, the flared end 51 of this embodiment may beenergized by the choice of materials or other geometricalcharacteristics of the flared end. In one example, the flared end may beformed as a composite of different materials having differentproperties.

In still further embodiments of the present invention, the energizing ofthe flared end is achieved with an energizing member 60 as best shown inFIGS. 3-4. As illustrated, the energizing member 60 can be at leastpartially located within the recess 62 of the seal 50. It is understoodthat the energizing member 60 may alternatively be substantially orentirely located within the recess. Furthermore, the energizing member60 may be encapsulated within the flared end of the seal. For example,the energizing member may be fabricated from a different material andthen embedded and concealed within the flared end.

Various types of energizing members 60 could be utilized. For example,due to differing material properties, the energizing member could thenact to energize the flared end 51 of the seal. In other examples, awedge could be used as the energizing member to cause the flanges tobias away from one another. In other examples, the energizing membercould take the form of a pressurized bladder, an O-ring, or materialcompressed within the flared end of the seal, or any material orcomponent suitable to cause the flanges 52 and 54 to bias away from oneanother. With respect to other aspects of the inventions, it will beunderstood that other shapes of energizing members could be used such asenergizing members with square, rectangular, triangular, wedge-shaped,or other cross sectional shapes, or that the energizing member could beremoved. Moreover, while a single energizing member is illustrated inthe embodiments, it is understood that a plurality of energizing memberscould be provided, and that the energizing member need not be unitary innature. For example, a plurality of spaced, or overlapping energizingmembers might be placed within a recess. For instance, a plurality ofO-rings could be stacked, one upon another, or concentrically arranged.In addition, a plurality of energizing members, such as spheres or ballbearings could be radially arranged at least partially within the recessof the seal. Similarly, it will be understood that the seal 50 could beformed with a plurality of recesses that can each receive one or moreenergizing members. With respect to some embodiments incorporatingaspects of the inventions, the energizing member could take other forms,such as a hollow ring. In still other embodiments, the energizing membermay take the form of a coil spring, or similar arrangement, connectedend-to-end in the shape of a torus.

Returning to FIGS. 1-4, and in particular as best shown in FIGS. 4 a and4 b, in some embodiments it has been found advantageous to use anenergizing member 60 that takes the form of a cantilevered spring. Inparticular, the figures depict the energizing member 60 in the form of acantilever spring, comprising a plurality of fingers which serve toprovide a force against the seal 50, to improve sealing performance.FIGS. 3 a, 3 b, and 4 b illustrate the seal 50 and cantilever spring 60of this embodiment in more detail. FIG. 4 a illustrates the cantileverspring 60, without the seal 50 which retains the spring. As shown inthese figures, the spring 60 is disposed in the recess 62 of the seal50, and comprises a cantilever spring having a plurality of fingers 92.Each of the fingers 92 runs between an inner wall 94 of the seal 50 andan outer wall 96 of the seal, the inner and outer walls defining therecess of the open, hollow, donut-shaped seal 50. Accordingly, thefingers 92 are each bent or otherwise disposed in a general U-shapewithin the recess 62. To hold the fingers 92 within the seal 50, theseal can be provided with an inner top lip 98 and an outer top lip 99,such that the two ends 93 of each finger 92 can be held under therespective inner surfaces 98′ and 99′ of these lips, and thereby beretained from exiting the open end 51 of the seal 50. Alternatively,other structures can be provided to hold the spring 60 within the seal50.

In addition, in this embodiment, the fingers 92 are connected at theirends 93, such as by an integral connection, which allows the spring 60to form a single continuous unit from its two end points. By positioningand retaining the spring 60 in the recess 62 in this manner, the fingers92 of the spring provide a substantially uniform or constant force orload on the inner and outer walls 94 and 96 of the seal 50. It has beenfound that this arrangement can provide improved sealing performance ofthe lip 64 against the stem 20 and of the lip 66 against the sleeve 30,even under varying loads, pressures, and conditions.

As an alternative to the cantilever spring 60, other finger-typesprings, flexible fingers, or flexible linear members might be utilized.Such members can be disposed, bent, or compressed between the inner andouter walls 94 and 96 to provide force on these walls to improve theperformance of the seal 50.

Other embodiments are also possible. For example, FIG. 5 depicts anotherembodiment of a stem seal module 70 made and operating according toprinciples of the present inventions. In this embodiment, the module 70includes a retainer or cap 72, which can be made of a suitable material,such as a material that will reduce friction with the stem 20. Forexample, a metal or metal alloy could be utilized, such as an aluminumbronze alloy like AMPCO 18. The retainer 72 can include a threadedportion 73 for threadably engaging the body or housing 12 of the nozzle,and thus for allowing the ease of insertion and removability of themodule 70. Other engagements between the retainer 72 and the body 12could be utilized as alternatives. The retainer 72 includes a centralpassage or opening for receiving the stem 20 and allowing the stem tomove freely upwardly and downwardly within the passage, in order toselectively permit and restrict the flow of fluid through the dispenser.

In addition, the module 70 includes an insert 74 also having a centralpassage or opening 71 for receiving the stem 20. The insert 74 alsoengages the retainer 72 forming a two piece module with an internalchamber. In particular, in this example, the retainer 72 includes areduced diameter portion 77 having a diameter D₂, while the insert 74includes thin upper walls 79 having a spacing slightly larger than thediameter D₂ such that the walls 79 of the insert 74 surround the reduceddiameter portion 77 of the retainer 72, until the upper surface of thewalls abut the larger portion of the retainer 72. Thus, the retainer 72is nested within the insert 74. Other structures for engaging themembers 72 and 74 can be provided, such as by interference fittings,other piloted configurations, and/or threadable engagements or similarinterlocking arrangements, for example. Because the distance betweenopposite surfaces of the walls 79 is larger than the diameter of theremainder of the central passage 71 of the insert 74, a recess 78 iscreated, which is enclosed by the retainer 72 once the retainer andinsert are engaged with one another. This recess 78 allows the module 70to be assembled with and house a seal when it is engaged with anddisengaged with the housing 12.

In particular, the module 70 further includes a seal 50 that can beretained by the removable module, even before it is engaged with thehousing 12. In particular, in this example, the seal 50 is held withinthe recess 78. The seal 50 provides a sealing interface with the stem 20as it moves in the dispenser. The seal can comprise a flanged seal withan internal energizing member, such as has been described above withrespect to FIGS. 3-4, or other suitable sealing member.

In this example, the removable module 70 also includes a seal 76 thatprovides a seal against the housing 12. This seal 76, in thisembodiment, is separate from seal 50 which does not seal against thehousing but rather seals against the stem 20. Accordingly, the functionsof sealing against the stem 20 and against the housing 12 are providedby separate seal structures in this embodiment. The seal 50, which canmove slightly due to the stem movement, is isolated from and does notcontact the potentially porous material of the housing 12, but rathercontacts the insert 74 which can be made of a smooth, low-friction,and/or non-porous material, such as a metal or metal alloy like AMPCO 18for example. Similarly, seal 76 is does not contact the stem, and isisolated from the stem movement, such that it experiences littlemovement against the porous housing 12. Accordingly, improved durabilityand performance are achieved in this embodiment.

To retain the seal 76 on the module, a second recess 80 is provided andis defined by and resides between inner extension 81 and outer extension83. Accordingly, the seal 76 at least partially resides within therecess 80. However, seal 76 may be sized slightly larger than therecess, such that, when the module 70 is threaded into the housing 12,the seal 76 is compressed or crushed against the lower surface 84 of theinner chamber 17 for the poppet stem assembly, defined within thehousing 12. For example, the seal 76 could comprise a crush seal O-ringmade of a suitable material, such as an elastomer material. In thisexample, the extension 81 of the insert 74 engages the poppet stemopening formed in the housing 12 (at the bottom of chamber 17).Accordingly, the poppet stem 20 slidingly engages the insert 74 at thislocation as well.

To assemble the module 70 of this example, the seal 76 can be placedaround the extension 81 of the insert 74 and pushed along the extensionuntil it rests in the recess 80. The seal 50 can be placed within therecess 78, and the retainer 72 can then be engaged with the insert 74.Accordingly, at this point, the seals 50 and 76 are held or retained bythe module members. This assembly can occur separate from the fueldispenser and without the need for separate tools or for carefulplacement of the seals within the dispenser. The module 70 can then beengaged with the housing 12, such as by threading the retainer 72 intothe housing chamber 17. While threading the retainer 72, the seal 76compresses against the housing surface 84, providing a fluid tight crushseal against the housing. The poppet stem 20 can be slided through themiddle of the module 70, and thus resides at the center of and issurrounded by the retainer 72, the seal 50, the insert 74, and the seal76. All of these components in this embodiment therefore have a passagethrough their center having a diameter, at least at some portion, thatis approximately the same as or slightly larger than the diameter of thestem 20. The seal 50 can include a flange or extension that abuts thestem 20 to provide a fluid tight seal against the stem. As the stem isinserted through the module 70, the seal 50 can compress radially withinthe recess 78 to provide the sealing force against the stem. The recess78 restrains the seal 50 from movement as the stem 20 slides up and downagainst the seal 50 during use. The low friction material of the insert74 results in reduced wear on the seal 50 as the stem moves. The seal 76is isolated from the stem 20 and therefore does not move in response tothe stem.

FIGS. 6 and 7 depict embodiments of fuel dispensing assemblies made andoperating according to principles of the present inventions, each beingfitted with the sliding stem seal modules of FIGS. 2 and 5 respectively.These embodiments illustrate components that can be included, as desiredor appropriate, when the inventive principles are applied to a fueldispensing assembly. Examples of some such components will now bebriefly described. In this example, the assembly includes a main body101/201, such as can be made of cast aluminum, and a stem assembly102/202, which can include a stainless steel stem and a wear resistanttip. The sealing system in these embodiments can include a removablemodule 28/70 which assists in retaining one or more seals (50 and48/76), even when the module 28/70 is disengaged from the fueldispenser, as was described in detail above.

A manual lever or actuator assembly 119/219 can also be provided, whichin this example includes a lever, a lower lever, a trigger, a spring tobias the trigger, and a rivet for securing the components. Near the topof the stem is provided a disc holder 108/208 which retains a disc109/209, both of which are provided on a skirt 110/210. These componentsserve as an interface between the stem and the main spring 111/211 whichbiases the stem. O-rings 112/212 or similar seals can be provided forsealing of components, as shown. A filter screen 154/254 can also beprovided to filter the pressurized fuel flowing through the nozzle fromthe inlet end 180/280 to the outlet end 190/290. A guard sub-assembly123/223 can also be provided to guide and protect the lever 119/219, andcan include a guard piece, a rack, and a rivet.

The operation of the lever assembly 119/219 with respect to the stemassembly 102/202 can be similar to that described above with respect tothe other embodiments. In particular, movement of the poppet stem102/202 by the lever 119/219 can move the skirt 110/210 and disc 109/209off of their seat, permitting fuel to flow through the housing, and inparticular, from the inlet end 180/280, around the poppet stem 102/202and shut off components held within the housing (described below), andout the spout end 190/290.

Another spring 143/243 can be provided between a body cap 113/213 and avapor valve 141/241, which can comprise, for example, a valve body, astem 142/242, a lip seal, an insert, retaining rings, and a disc anddisc holder. The spring 143/243 can be used for biasing the vapor valve.Another retaining ring 135/235 can be provided for retention ofcomponents. The vapor valve can operate as known in the art for flow ofvapors.

In addition, a shut-off valve assembly 132/232 can be provided forautomatic shut off of the fuel flow upon detection of a full conditionin a fuel tank. This assembly can include a diaphragm biased by aspring, a support cup, a support, and other components such as asnubber, a wear washer, and a cap. In addition, a diaphragm sub-assembly133/233 can be provided, which can include a diaphragm and diaphragmsupport, a lower diaphragm connector, a flat washer, and an upper pinand spring pin. Additional shut-off components can include a diaphragmspring 114/214, a latch spring 115/215, a latch ball 122/222, a latchring 134/234, and a latch plunger 116/216, and the shut-off componentscan connect with the lever 119/219 via a plunger pin 120/220 and pushnut 121/221. These components can operate in ways known in the art, orlater to be developed, for automatic shut off of the nozzle, such as byusing Venturi vacuum principles for example.

The spout end of the fueling nozzle can include a spout sub-assembly118/218 including a tube, spring, poppet, bleeder seat ring/outer tube,sleeve, and ferrule, as well as various O-rings for sealing, andretaining rings for securing components. A vapor escape guard 148/248,and clamp 149/249 therefor, can also be provided to prevent escape ofvapors. An anchor spring 155/255 and ring 156/256 can also be utilized.The spout components can operate as known in the art or in a desiredmanner.

Other components can also be provided, as needed or desired, to createthe appropriate fueling nozzle for the application at issue. Forexample, rivets 125/225 and screws 130/230 can be provided for securingcomponents together, insulating material 126/226 and 140/240 can beprovided to insulate the metal pieces from the user, identificationwasher 136/236 and screw 137/237 can be provided for identification ofthe nozzle, and O-rings 138/238, 139/239, 128/228, 129/229, and 124/224can be provided for appropriate sealing of components.

The modules 28 and 70 of these embodiments therefore operate to sealfluid from leaking along the stem or along the main body. These modules28 and 70 can exhibit increased durability and performance and reducedassembly requirements.

The foregoing description of the various embodiments of the inventionhas been presented for the purposes of illustration and description. Itis not intended to be exhaustive or to limit the inventions to theprecise form disclosed. Many alternatives, modifications and variationswill be apparent to those skilled in the art of the above teaching. Forexample, although the module is shown as comprising multiple engagedmembers and two seals in some embodiments, the module could comprise asingle integrated component and/or a single seal in other embodiments ofthe invention. As another example, although multiple inventive aspectshave been presented, such aspects need not be utilized in combination,and various combinations of aspects are possible in light of the variousembodiments provided above. Accordingly, it is intended to embrace allpossible alternatives, modifications, combinations, and variations thathave been discussed and suggested herein, and all others that fallwithin the principles, spirit and broad scope of the inventions asdefined by the claims.

1. A fluid dispenser comprising: a fluid dispenser housing comprising aninner chamber defined by a chamber surface; a cylindrical stem includingan outer surface, said stem being configured to control the flow offluid through said housing; an insertable module selectively engagedwith said inner chamber and including an opening slidingly receivingsaid stem; a stem seal member retained by said module and in sealingcontact with said outer surface of said cylindrical stem when saidmodule is engaged with said inner chamber to provide a first seal,wherein said stem seal member is separated from said housing by aportion of the module and wherein said stem seal member contacts saidstem and a substantially non-porous portion of said module; and ahousing seal member retained by said module and in sealing contact withsaid chamber surface of said housing when said module is engaged withsaid inner chamber to provide a second seal, wherein said housing sealmember is separated from said stem by a portion of said module wherebysaid second seal provides a static seal against said chamber surface;wherein said module is configured to retain said stem seal member andsaid housing seal member when said module is disengaged from saidchamber.
 2. The dispenser as recited in claim 1, wherein said stem sealmember comprises at least one flange and includes an internal energizingmember.
 3. The dispenser as recited in claim 2, wherein said flangecontacts said outer surface of said stem to provide a lip-like seal whensaid module engages said inner chamber.
 4. The dispenser as recited inclaim 1, wherein said module includes a first recess for retaining saidstem seal member and a second recess for retaining said housing sealmember.
 5. The dispenser as recited in claim 1, wherein said modulethreadably engages said housing chamber.
 6. The dispenser as recited inclaim 1, wherein said module comprises at least two engaged members. 7.The dispenser as recited in claim 6, wherein said stem seal member isretained between said engaged members.
 8. The dispenser as recited inclaim 1, wherein said housing seal member comprises at least one O-ring.9. The dispenser as recited in claim 8, wherein said O-ring contactssaid chamber surface of said housing to provide a ring-like seal in use.10. A fluid dispensing assembly comprising: a main body including aninlet port adapted to communicate with a source of pressurized fluid andan outlet port adapted to dispense fluid from said main body, whereinsaid main body includes an inner chamber defined by a chamber surface; astem including an outer surface, wherein said stem is adapted to assistin regulating fluid between said inlet port and said outlet port of saidmain body a stem seal including an opening slidably receiving said stemand comprising an inner sealing surface, wherein said inner sealingsurface sealingly contacts said outer surface of said stem to provide afirst seal; a body seal sealingly contacting said chamber surface ofsaid body to provide a second seal; a module configured to selectivelyengage said inner chamber and including an opening for receiving saidstem, wherein said module is adapted to retain said stem seal and saidbody seal when said module is disengaged from said chamber, and whereinsaid stem seal provides said first seal against said stem when saidmodule engages said inner chamber and wherein said body seal providessaid second seal against said chamber surface when said module engagessaid inner chamber; and a manual actuator adapted to control movement ofsaid stem and control the flow of fluid through said main body.
 11. Theassembly as recited in claim 10, wherein said stem seal is isolated fromthe main body and is held between said stem and a substantially smoothsurface of said module.
 12. The assembly as recited in claim 10, whereinsaid stem seal includes at least one flange, and wherein said stem sealcomprises a Teflon material and includes an energizing member includedwithin said stem seal.
 13. The assembly as recited in claim 10, whereinsaid module includes at least two engaged pieces.
 14. The assembly asrecited in claim 10, wherein said module includes a first void forretaining said stem seal and a second void for retaining said body seal.15. The assembly as recited in claim 10, wherein said body seal isisolated from movement of said stem, and wherein said stem seal isisolated from said body.
 16. The assembly as recited in claim 10,further comprising a shut-off actuator configured to automatically shutoff flow of fluid through said main body in response to a fillcondition.
 17. A fuel dispenser comprising: a main body including aninlet port adapted to communicate with a source of pressurized fuel andan outlet port adapted to dispense fuel from said main body, whereinsaid main body includes an inner chamber defined by a chamber surface; aseal comprising a sealing surface, wherein said sealing surfacesealingly contacts a component of said fuel dispensing assembly toprovide a first seal; an insertable retainer configured to selectivelyengage said inner chamber, wherein said retainer is adapted to retainsaid seal when said retainer is disengaged from said chamber, andwherein said seal provides said first seal against said assemblycomponent when said retainer engages said inner chamber; a manualactuator adapted to control the flow of fuel through said main body; anda shut-off actuator configured to automatically shut off flow of fuelthrough said main body in response to a fill condition.
 18. The fueldispenser as recited in claim 17, wherein said seal is isolated fromsaid main body and is held between said component and a low frictionsurface of said retainer.
 19. The fuel dispenser as recited in claim 17,wherein said component comprises a moving component separate from saidmain body, and wherein said dispenser further comprises a second sealretained by said retainer and isolated from said moving component,wherein said second seal contacts said main body and wherein said firstseal is isolated from said main body by said retainer.
 20. A method forassembling a fuel dispensing apparatus, the method comprising: placing aseal on a module such that said seal is held on said module; providingcomponents for assembling a fuel dispensing apparatus; engaging saidmodule with a housing for a fuel dispensing apparatus, such that saidseal contacts at least one of said housing and said components andprovides a fluid-tight seal therewith; and assembling said componentsand said housing as a fuel dispensing apparatus.
 21. The method asrecited in claim 20, wherein said module engages said housing by athreaded engagement, and wherein said seal is placed within a recess ofsaid module.
 22. The method as recited in claim 20, wherein said sealcomprises a poppet stem seal, wherein one of said components comprises apoppet stem, and wherein the method further comprises: placing saidpoppet stem through said module and said seal.
 23. The method as recitedin claim 20, wherein one of said components comprises a poppet stem andwherein said seal contacts said poppet stem and is isolated from saidhousing by said module, and wherein said method further comprises:placing a second seal on said module whereby said second seal isisolated from said poppet stem by said module, and wherein said secondseal sealingly contacts said housing upon engaging said module with saidhousing.
 24. The method as recited in claim 20, further comprising:engaging a first piece of said module with a second piece of said modulesuch that said seal is held between said two pieces.
 25. A fluiddispenser comprising: a fluid dispenser housing comprising an innerchamber defined by a chamber surface; a poppet stem assembly residingwithin the inner chamber and comprising: a cylindrical stem including anouter surface, said stem being configured to control the flow of fluidthrough said housing; a stem seal member in sealing contact with saidouter surface of said cylindrical stem to provide a first seal, whereinsaid stem seal member does not contact said housing; and a housing sealmember in sealing contact with said chamber surface of said housing toprovide a second seal, wherein said housing seal member does not contactsaid stem.
 26. The dispenser as recited in claim 25, wherein said stemseal member is located between a low friction surface and said stem. 27.The dispenser as recited in claim 25, wherein said stem seal member andsaid housing seal member are retained by an insertable module.